MIT OpenCourseWare http://ocw.mit.edu

11.479J / 1.851J Water and Sanitation Infrastructure in Developing CountriesSpring 2007

For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.

Water QualitySusan Murcott

Water and Sanitation Infrastructure in Developing Countries

Week 6, 11.479 J / 1.851J March 13, 2007

Outline• Does “Improved” = “Safe?”

Two “Safe Water” Definitions• Four Water Quality Categories• Water Quality Lab

– Bacterial Indicators – Turbidity– Residual Chlorine

• EPA & MWRA Water Quality Regulations• Vietnam Water Quality Regulations

Are “Improved” Drinking Water Supplies Safe?

• Gundry et al (2006):• Rural South Africa and Zimbabwe• Randomized study – 254 children, aged 1-2 years• Dry and wet seasons

> 10 CFU/100ml E.coli

Improved(standpipe,

borehole, protected well)

Unimproved(unprotected well/spring, river/canal)

At Source 12% 71%

Household Storage 41% 81%

Drinking Cup 51% 82%

“Safe Water” - Definition

• “We define safe drinking water as water that is safe to drink and available in sufficient quantities for hygienic purposes”

(UN Millennium Task Force, 2005)

“Safe Water” – DefinitionWHO GDWQ 3rd Ed.

• “Safe drinking water, as defined by the Guidelines, does not represent any significant risk to health over the lifetime of consumption, including different sensitivities that may occur between life stages.”(p.1)

• “Those at greatest risk of waterborne disease are infants and young children, people who are debilitated or living under unsanitary conditions and the elderly.” (p.1)

• “The judgment of safety - or what is a tolerable risk in particular circumstances – is a matter in which society as a whole has a role to play. The final judgment as to whether the benefit resulting from the adoption of any of the health-based targets justifies the cost is for each country to decide.” (p.37)

Water Quality – 4 Broad Categories

Microbiological• Bacteria

• Viruses

• Protozoa

• Helminthes

Chemical• Organic / Inorganic

• Naturally occurring /

• Anthropogenic

• Turbidity

• Odor

• Taste

• Appearance

• other…

Physical / Aesthetic Radionuclides

• Radium

• Uranium

• Radon

Microbiological Contaminants

• “Infectious diseases cased by pathogenic bacteria, viruses, protozoa and helminthes are the most common and widespread health risk associated with drinking water.”

• (WHO, 2004. Guidelines For Drinking Water Quality 3rd Ed. p. 123)

Indicator Organisms• Organisms, whose presence indicate likely occurrence of

waterborne pathogens:

[indicator] fecal contamination [pathogen] ≈ disease

• Ideal indicators should fulfill several criteria:– Always be present when pathogens are present;– Share similar persistence and growth characteristics;– Exist in larger concentrations for easy detection;– Detection tests should be relatively simple,

inexpensive;– Detection tests should detect indicator org. only;– Detection tests should be applicable to all types of

water.

Pathogens vs. Indicator OrganismsPathogens Indicator Organisms

Cause disease directly Most are not pathogenic

Great variety Specific target groups

Difficult to isolate

Takes longer to detect

Easy to detect and enumerate, usually within 24-48hrs

Some are opportunistic

Note !!! Direct detection of pathogens is inappropriate for routine water monitoring, because, based on methods available today, it is complex, time-consuming and expensive. Instead, frequent and simple indicator tests are better, especially when contamination can be intermittent and/or undetectable.

What are coliforms? (WHO-GDWQ 3rd Ed.)• “Gram negative, rod-shaped bacteria, grown in bile

salts, fermenting lactose at 35-37ºC producing acid, gas, and aldehyde within 24-48hrs, oxidase negative, non-spore forming, display β-galactosidase activity.”

• Operational, not taxonomic definition.• First introduced ~120 years ago, based on its

quantifiable relationship with potential health risks.

Relationship between pathogen and coliform (Olson & Nagy, 1984)

0.100

0.010

0.001

0.00010-1 100 101 102 103

103

104

104 105 106 107 108

4.9x102 5.8x103 7.0x105 7.2x1066.5x104 7.1x107

Ris

k of ill

nes

s (%

)

Salmonella/litre

Coliform (MPN/100mL)

Faecal coliform (MPN/100mL)Figure by MIT OpenCourseWare.

Coliform Indicator Organisms• The coliform group is the most common indicator group

used in the world. It includes:– Total Coliform– Thermotolerant coliform (formerly known as “fecal”)– E.Coli

• Fecal coliforms are nowadays more properly referred to as “thermotolerant coliforms” Thermotolerant coliform are those able to ferment lactose at 44-45° C. The name-change is due to the fact that some in this group may be of non-fecal origin.

• For example, in tropical areas, total coliforms can originate from decaying vegetation and do not necessarily indicate the presence of pathogens in water

• Still, these indicators are used in the tropics due to lack of better methods

• Fecal streptococci and clostridia are other bacterial indicator groups commonly used in temperate climates.

E. coli

• Exclusively fecal in origin • WHO defn: Thermotolerant coliforms with

indole production and beta-glucuronidase activity and absence of urease activity

• Constitutes 90 - 95% of the coliform bacterial in mammalian fecal material

• Most sensitive and specific indicator of fecal pollution currently available as well as most widely used, world-wide

WHO-Guideline Value for Verification of Microbial Water Quality

from: GDWQ – 3rd Edition

• E.coli or thermotolerant coliform bacteria must not be detected in any 100 ml sample for all water directly intended for:– Drinking;– Treated water entering the distribution

system;– Treated water in the distribution system.

From Table 7.7 p. 143. See also Table 5.2. p. 97

Proportion (%) of Samples Negative for E.coliPopulation Size->Water Quality

< 5000 5,000 –100,000 > 100,000

Excellent 90 95 99

Good 80 90 95

Fair 70 85 90

Poor 60 80 85

E. coli Grading Schemes

“In many developing and developed countries, a high proportion of small-community drinking water systems fail to meet requirements for water safety. In such circumstances, it is important to set realistic goals… and classify water quality results in terms of an overall grading systems,” as illustrated here: (WHO, GDWQ, 3rd Ed. 2004 p. 97)

Thermotolerant (Fecal) Bacteria Risk Categories

for Untreated Rural Water Supplies

Count per 100ml Risk Category

0 Conforms with WHO Guidelines

1 – 10 Low Risk

10 – 100 Intermediate Risk

100 – 1000 High Risk

> 1000 Very High Risk

WHO. Guidelines for Drinking Water Quality, 2nd Ed. Vol. III, Surveillance and Control of Community Supplies, Geneva, 1997)

Why coliforms are imperfect indicators1. Coliforms regrow (or are suppressed) in the

environment– In enriched waters, even chlorinated sewage, on

biofilms in distribution systems.– E.coli is 2,400 times more resistant to chlorine when

attached to a surface (turbid water) than as free cells.– Presence of background antagonistic bacteria can

reduce coliform counts up to 57%.

Regrowth of coliforms and E.coli in sewage effluent (Shuval et al., 1973)

Time (days)

Col

iform

s or E

. Col

i 100

mL-1

% b

acte

ria re

mai

ning

E. Coli

Coliforms

10

103

104

105

106

102

107

0.0001

0.001

0.01

0.1

1

10

100

0 1 2 3 4 5 6 7

Figure by MIT OpenCourseWare.

Coliforms imperfect (cont’d)

2. Inaccurate indicators of pathogens and waterborne diseases– Not necessary indicative of pathogenic bacteria,

protozoa, and viruses health threat. – Some outbreak studies show absence of coliform

when there is a outbreak and vice versa. Pathogenic Vibrio sp. and Salmonella sp. have been recovered from waters containing few or no coliforms.

– Non-fecal Klebisella, Citrobacter or Enterobacter can be found naturally.

– Coliforms are not reflective of protozoan cysts and enteric viruses.

Coliforms imperfect (cont’d)Total coliforms Fecal coliforms Cryptosporidium Giardia

Turbidity Moderate (0.28) Moderate (0.29) Low (0.24) Moderate (0.28)

Total coliforms High (0.71) Low (0.15) None (0.02)

Fecal coliforms Moderate (0.29) Low (0.10)

Cryptosporidium High (0.78)

Correlation for coliform, turbidity, and protozoa in a watershed. (Rose et al., 1988)

Coliforms imperfect (cont’d)3. High probability of false positive and false negative

results– Existence of non-coliforms with similar operational

behavior e.g. Aeromonads, can give false positives.– Some 20% of coliforms are non-lactose forming.

4. Inappropriate as fecal indicators in tropical waters– Many coliforms, many thermotolerant, are naturally

occurring in tropical waters need alternative indicator

– E.coli is preferred as it represents 90 - 95% of all coliforms found in feces.

– Fecal streptococci, clostridium perfringens are almost certain of fecal origin can also be used.

WHO 3rd Edition GDWQ

• There is no single “ideal” indicator organism.

• The new 3rd Edition WHO Guidelines for Drinking Water Quality seek to address this with its risk-based approach

Appropriate health risk vs. cost of maintaining Appropriate health risk vs. cost of maintaining high level of water quality?high level of water quality?

“…“… to encourage an to encourage an incrementalincremental improvement improvement in water quality at in water quality at most affordablemost affordable cost.cost.””

WHO 3rd Ed. GDWQ1. Evaluate “acceptable risk”

– Quantify risk of infection, infective dose, opportunistic pathogens.

– Can be based on incremental benefit/cost ratios.

– Require lots of epidemiological data.

2. Conduct proper sanitary surveys– Investigate and eliminate contamination

near water source.– Require conscientious carrying out of

maintenance (e.g. tubewell) programs.– Sanitation improvements go hand in hand.

Approaches (Cont’d)3. Develop Water Safety Plans based on acceptable risk

– Encourage attainable, incremental improvement in water quality.

– Guidelines should be future goals, not immediate requirement.

4. Use simple, inexpensive monitoring tests– Encourage simple, yet frequent water monitoring

practices.– Household kits adjusted to appropriate sensitivity to

prevent false-positives.– Still, ultimate goal is direct detection of pathogens.

Water Quality Lab

Simple, Inexpensive Tests for Operational Monitoring

Turbidity

• Suspended and colloidal particles of clay, silt, organic and inorganic matter, minerals, plankton and microscopic organisms which impede the passage of light through water.

• Turbidity > 5 NTU is noticeable to the consumer

• Effective coagulation / filtration should removal turbidity

Turbidity Measurement & Units• Jackson Candle Units – the historic standard

method, however the lowest value measured is 25 Jackson Turbidity Units (JTU) and treated water usually falls in the range 0 – 1 JTU.

• -> So… electronic nephrelometers were developed• Nephrelometers are turbidimeters which measure

intensity of light scattered at 90° to the incident beam.”

• There is no standard type of turbidity, so an arbitrary standard is used in electronic nephrelometers, composed of an aqueous suspension of formazin polymer.

• Unit of measurement = nephrelometric turbidity unit (NTU)

Coliform Indicator Tests

3 common methods • Presence/Absence• Most Probable Number (MPN)• Membrane Filter (MF)

Total Coliform / E.Coli Presence Absence Test Result

Negative for TC/E.Coli Positive = yellow for TC

Total Coliform/E.Coli P/A Test showing fluorescence for E.Coli ( = + for E.coli)

Yellow = + for total coliform

Yellow & fluorescence = + for E.Coli

Hydrogen Sulfide Bacteria Presence/Absence Results

Absent = negative Present = positive

Simplified Membrane Filtration Set-up

Membrane Filtration Setup with Portable Filtration Unit

m-Endo broth medium for Total Coliform (TC). Colonies are gold-green with sheenafter incubation at 35 degrees C for 24 hours

m-Coli blue broth medium for simultaneous TC/E.coli. TC are red; E.Coli are blue colonies after incubation at 35 degrees C for 24 hours

m-FC broth for thermotolerant coliform -> blue colonies after incubation at 44.5 degrees C for 24 hours

E Coli bacteria fluoresce under UV light due to MUG in medium

3M Petri-film: a new

membrane filtration method

E. coli E. coli & & Total coliformTotal coliform

Chlorination

Most common forms of chlorine:

• Dry (calcium hypochlorite –[Ca(OCl2)]

• Liquid (sodium hypochlorite –(NaOCl)=bleach

• Chlorine gas (Cl2)

Chlorination Chemistry• Free residual chlorine (a.k.a. free available chlorine) = quantity of hypochlorous

acid (HOCl) and hypochlorite ion (OCl-) in the water. The relative distribution of these two species is very important, because the killing efficiency of HOCl is about 40 – 80 x greater than OCl- .

• Ammonia, commonly present in natural waters, will react with HOCl or OCl- to form monochloraine, dichloramire and trichloramine, depending on factors such as temperature and pH.

• Chlorination of water to the extent that all ammonia is converted to either trichloramine or oxidized to nitrogen or other gases is referred to as “breakpoint chlorination.”

• Before breakpoint, “combined” chlorine predominates (monochloramine + dichloramine)

• After breakpoint, free available chlorine predominates (hypochlorous acid + hypochlorite)

• Combined Residual Chlorine (ppm) + Free Residual Chlorine = Total Residual Chlorine

Breakpoint Chlorination CurveCombined Residual + Free Residual = Total Residual Chlorine

(Hach, undated)

Chlorine Dose

Res

idua

l Con

cent

ratio

n

Break-Point

Combined Residual Free Chlorine Residual

(Mainly Monochloramine)

Figure by MIT OpenCourseWare.

Breakpoint Chlorination Curve

(Metcalf & Eddy, 2003)

Chlorine dose, mg/L

Combinedresiduals

Free andcombinedresiduals

Freeresidual

Combinedresidual

Breakpoint

1

1

2

2

3

3

4

4

5

5

6 7 8 9 1000

Destruction of chlorineresidual by reducingcompounds

Formation of chloro-organic and chloraminecompounds

Destruction ofchloramines and chloro-organic compounds

Formation of free chlorineand presence of chloro-organiccompounds not destroyed

Chlo

rine

resi

dual

s, m

g/L

A

B

C

11

Figure by MIT OpenCourseWare.

How to Chlorinate your Water?Site Specific Context!!!• Chlorine dose must be determined using local chlorine

product with local water supply. This is because different waters have different “chlorine demand” characteristics.

General Procedure (in emergency or remote location situation and bleach is of unknown concentration):

• Add known amount of bleach (for example, 1 capful;• After 30 minutes, measure free residual chlorine. • If free residual chlorine is between 0.5 and 1.0 mg/l, the

dose is appropriate. • For a 20 L vessel, the required dose of a 0.5% chlorine

solution could, for example, typically be between 5-10 ml.

Water Quality Regulations

National Safe Drinking Water Act (SDWA)

• Enacted into law - Dec. 1974• Designed to achieve uniform safety and

quality of drinking water in the U.S. by identifying contaminants and establishing maximum acceptable levels for contaminants

• Primary Drinking Water Contaminants• Secondary Drinking Water Contaminants

Primary and Secondary Drinking Water Contaminants

• Primary Contaminants – those which have an adverse affect on public health

• Secondary Contaminants – those related to taste, odor or appearance

Safe Drinking Water Act –Regulatory Definitions

• EPA Administrator is directed to prescribe MCLs for contaminants (if economically and technically feasible), according to her/his best judgment (given > thousands of chemical compounds used commercially)

• Maximum Contaminant Levels “maximum permissible level of a contaminant in the water delivered to a user of a public water system.”

• Maximum Contaminant Level Goals

• Public Water System – at least 15 service connections or a system that regularly services at least 25 individuals at least 60 days/year.

What are the definitions?

KEY: MCL = Maximum Contaminant Level - The highest level of a contaminant allowed in water. MCLs are set as close to the MCLGs as feasible using the best available technology

MCLG = Maximum Contaminant Level Goal - The level of contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety

MRDL - Maximum residual disinfectant level. The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.

MRDLG - Maximum Residual Disinfectant Level Goal. The level of a drinking water disinfectant below which there is no known or expected health risk. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contamination.

ppm = parts per million ppb = parts per billion Avg = Average

1975 1976 1979 1986 1987 1989 1991 1992 1995 1998 1998 2000 2001

DRINKING WATER REGULATIONS - PAST

1822 23 23

3135

62

84 8389 90 91 91

0

10

20

30

40

50

60

70

80

90

100

Num

ber o

f Con

tam

inan

ts R

egul

ated

Calendar YearCOMPLETED

INTE

RIM

RAD

s

INTE

RIM

MC

Ls

TTH

Ms

FLU

OR

IDE

VO

LATI

LE O

RG

ARN

IC C

HE

MIC

ALS

SU

RFA

CE

WAT

ER

TR

EATM

EN

T An

d C

OLI

FOR

MS

PHAS

E II

CO

&

Pb

PH

ASE

-V

Ni TT

HM

s

TUR

BID

ITY

RA

Ds

As &

RAD

s

1975 1976 1979 1986 1987 1989 1991 1992 1995 1998 1998 2000 2001

Excerpt: EPA Primary Drinking Water Contaminantshttp://www.epa.gov/safewater/consumer/pdf/mcl.pdf

MWRA Water Testing and Water Regulations

What is regulated in the US?What does MWRA test for?

(Note: Some of the following MWRA slides are provided by Joshua Das 3/8/06)

J.Das - 3/8/06

Regulated Contaminant Groups• Radioactive • Microbiological • Inorganic• Secondary and Process Control• Chlorine and Chlorine By-products• Lead and Copper• Volatile Organic Compounds• Synthetic Organic Compounds• Unregulated Contaminant Monitoring Rule – VOCs, SOCs, DBPs,

Inorganic, Other

Radioactive, Microbiological, Inorganic

Inorganic Contaminants• ANTIMONY • ARSENIC • ASBESTOS • BARIUM • BERYLLIUM • CADMIUM • CHROMIUM • COPPER • CYANIDE • FLUORIDE • LEAD • MERCURY • NICKEL • NITRATE • NITRITE • SELENIUM • SODIUM • SULFATE • THALLIUM

Radioactive Contaminants• Beta/photon emitters particles • Alpha emitters • Combined radium • Uranium • Gross Alpha Particle Activity • Radium-226 • Radium-228

•Microbiological•TOTAL COLIFORM •E. COLI •GIARDIA •CRYPTOSPORIDIUM •VIRUSES •TURBIDITY •Heterotrophic Bacteria Plate Count

Secondary, Process Control, Chlorine/By-products, Pb & Cu

Chlorine and Chlorine By-Products • CHLORINE • CHLORAMINE • BROMATE • TOTAL • TRIHALOMETHANES • HALOACETIC ACIDS

Secondary Contaminants•TURBIDITY (NTU) •TDS •COLOR (COLOR UNIT) •ODOR (TON) •PH •ALKALINITY-TOTAL (CaCO3) •HARDNESS (CaCO3) •CALCIUM (Ca) •MAGNESIUM (Mg) •ALUMUNUM (Al) •POTASSIUM (K) •IRON (Fe) •MANGANESE (Mn) •SULFATE (SO4) •SILVER (Ag) •COPPER (Cu) •ZINC (Zn) Lead and Copper•LEAD (Pb) •COPPER (Cu)

Process Control •pH •Alkalinity •Color •Conductance •Free Chlorine •Total Chlorine •Monochloranime •Free Amonina •Nitrate/Nitrite •Total Organic Carbon •UV-254 •Fluoride

EPA Secondary Standards

• Contaminant Secondary Standard • Aluminum 0.05 to 0.2 mg/L • Chloride 250 mg/L • Color 15 (color units) • Copper 1.0 mg/L • Corrosivity noncorrosive • Fluoride 2.0 mg/L • Foaming Agents 0.5 mg/L • Iron 0.3 mg/L • Manganese 0.05 mg/L • Odor 3 threshold odor number • pH 6.5-8.5 • Silver 0.10 mg/L • Sulfate 250 mg/L • Total Dissolved Solids 500 mg/L • Zinc 5 mg/L

VOCsVolatile Organic Contaminants -Regulated

Contaminants• 1,1,1-TRICHLOROETHANE • 1,1,2-TRICHLOROETHANE • 1,1-DICHLORETHYLENE • 1,2,4-TRICHLOROBENZENE • 1,2-DICHLOROETHANE • 1,2-DICHLOROPROPANE • BENZENE • BROMATE • CARBON • TETRACHLORIDE • CHLORITE • CHLORINE DIOXIDE • CIS-1,2-DICHLOROETHYLENE • DICHLOROMETHANE • ETHYLBENZENE • MONOCHLOROBENZENE • O-DICHLOROBENZENE • PARA-DICHLOROBENZENE • STYRENE • TETRACHLOROETHYLENE • TOLUENE • TRANS-1,2-DICHLOROETHYLENE • TRICHLOROETHYLENE • TTHMS • VINYL CHLORIDE • XYLENES (TOTAL)

Volatile Organic Contaminants -Unregulated Contaminants

• 1,1,1,2-TETRACHLOROETHANE • 1,1,2,2-TETRACHLOROETHANE • 1,1-DICHLOROETHANE • 1,1-DICHLOROPROPENE • 1,2,3-TRICHLOROBENZENE • 1,2,3-TRICHLOROPROPANE • 1,2,4-TRIMETHYLBENZENE • 1,3,5-TRIMETHYLBENZENE • 1,3-DICHLOROPROPANE • 1,3-DICHLOROPROPENE • 2,2-DICHLOROPROPANE • BROMOBENZENE • BROMOMETHANE • CHLOROETHANE • CHLOROFORM • CHLOROMETHANE • DICHLORODIFLUOROMETHANE • FLUOROTRICHLOROMETHANE • HEXACHLOROBUTADIENE • ISOPROPYLBENZENE • M-DICHLOROBENZENE • METHYL TERTIARY BUTYL ETHER • NAPHTHALENE • N-BUTYLBENZENE • N-PROPYLBENZENE • O-CHLOROTOLUENE • P-CHLOROTOLUENE • P-ISOPROPYLTOLUENE • SEC-BUTYLBENZENE • TERT-BUTYLBENZENE

SOCsSynthetic Organic Contaminants -

Regulated Contaminants

• 2,3,7,8-TCDD (DIOXIN) • 2,4,5-TP (SILVEX) • 2,4-D • ALACHLOR • ATRAZINE • BENZO(A)PYRENE • CARBOFURAN • CHLORDANE • DALAPON

DI(ETHYLHEXYL)ADIPATE • DI(ETHYLHEXYL)PHTHALATES • DIBROMOCHLOROPROPANE

(DBCP*) • DINOSEB • DIQUAT • ENDOTHALL • ENDRIN

• EPICHLOROHYDRIN • ETHYLENE DIBROMIDE (EDB)* • GLYPHOSATE • HEPTACHLOR • HEPTACHLOR EPOXIDE • HEXACHLOROBENZENE • HEXACHLOROCYCLOPENTADIENE • LINDANE • METHOXYCHLOR • OXAMYL (VYDATE) • PCB AROCLOR 1016 • PCB AROCLOR 1221 • PCB AROCLOR 1232 • PCB AROCLOR 1242 • PCB AROCLOR 1248 • PCB AROCLOR 1254 • PCB AROCLOR 1260 • PCB'S (DECACHLOROBIPHENYL) • PENTACHLOROPHENOL • PICLORAM • SIMAZINE • TOXAPHENE

Unregulated ContaminantsSynthetic Organic Contaminants -

Unregulated Contaminants • 3-HYDROXYCARBOFURAN • ALDICARB • ALDICARB SULFONE • ALDICARB SULFOXIDE • ALDRIN • BUTACHLOR • CARBARYL • DICAMBA • DIELDRIN • METHOMYL • METOLACHLOR • METRIBUZIN • PROPACHLOR

Disinfection By-Products -Unregulated Contaminants

• Haloacetilenitriles • Haloketones • Chloropicrin • Chloral Hydrate • Total Organic Halides • Cyanogen Chloride • Chlorate • Bromate • Aldehydes

Unregulated ContaminantsUnregulated Contaminant

Monitoring Rule Contaminants (List 1)

• 2,4-dinitrotoluene • 2,6-dinitrotoluene • Acetochlor • DCPA mono-acid degradate • DCPA di-acid degradate • 4,4'-DDE • EPTC • Molinate • MTBE • Nitrobenzene • Perchlorate • Terbacil

Unregulated Contaminant Monitoring Rule Contaminants (List 2)

• 1,2-diphenylhydrazine • 2-methyl-phenol • 2,4-dichlorophenol • 2,4-dinitrophenol • 2,4,6-trichlorophenol • Diazinon • Disulfoton • Diuron • Fonofos • Linuron • Nitrobenzene • Prometon • Terbufos • Aeromonas • Alachlor • ESA • RDX

Unregulated Contaminants (con’d)• Unregulated Contaminant Monitoring Rule Contaminants (List 3) • Lead-210 • Polonium-210 • Cyanobacteria • Echoviruses • Coxsackieviruses • Helicobacter pylori • Microsporidia • Caliciviruses • Adenoviruses • Other • Chloide • Bromide • Silica • Total Phosphorous

What Does MWRA Find?

Compound Units MCL d Level Range MCLG Violation How it Gets in the Water

0.009 -Barium ppm 2 0.011 0.011 2 No Common mineral in nature

Benzene ppb 5 2.1 1.6 - 2.1 0 No Not Known - See Below

4 -4 - Avg = 0.03 - MRDL

Chloramine ppm MRDL 1.26 2.20 G No Water disinfectant

Avg = Avg = 0.03 -Fluoride ppm 4 1.21 7.7* 4 No Additive for dental health

0.03 -Nitrate ppm 10 0.15 0.15 10 No Breakdown of disinfectants

Nitrite ppm 1 0.005 0.005 1 No Breakdown of disinfectants

Total Trihalomethan Avg = Avg = 44.2 - Byproducts of water

es ppb 80 74.4 110 0 No disinfection

Haloacetic Avg = Avg = 0.6 - Byproducts of water Acids - 5 ppb 60 36.6 61.7 0 No disinfection

Detecte

J.Das - 3/8/06

What else does MWRA test for?

Source Water• Turbidity• Fecal Coliform – Pre-treatment• Algae• UV-254

Turbidity Results –Quabbin

Quabbin Reservoir at Ware Disinfection FacilityAverage and Maximum Daily Turbidity Levels Leaving

Quabbin Reservoir

0.0

0.5

1.0

1.5

2.0

Jan-05 Apr-05 Jul-05 Oct-05 Jan-06

Turb

idity

(NTU

) ) Daily Maximum

Daily AverageMaximum Standard

Turbidity Results - WachusettWachusett Reservoir

Average and Maximum Daily Turbidity Levels Leaving Wachusett Reservoir

0.0

0.5

1.0

1.5

2.0

Jan-05 Apr-05 Jul-05 Oct-05 Jan-06

Turb

idity

(NTU

) ) Daily Maximum

Daily AverageMaximum Standard

Fecal Coliform Results –Pre-Treatment

Quabbin Reservoir Fecal Coliform Levels Before Disinfection

0

10

20

30

Jan-05 Apr-05 Jul-05 Oct-05 Jan-06

Feca

l Col

iform

(cfu

/100

mL)

Fecal Coliform Results –Pre-Treatment

Wachusett Reservoir Fecal Coliform Levels Before Disinfection

0

10

20

30

Jan-05 Apr-05 Jul-05 Oct-05 Jan-06

Feca

l Col

iform

(cfu

/100

mL)

Algae ResultsTotal Algae at Wachusett Reservoir

Maximum Result

0

600

1200

1800

2400

3000

Jan-05 Apr-05 Jul-05 Oct-05 Jan-06

asu/

mL

UV-254

UV 254Wachusett Reservoir Source Water

Grab Data

0.02

0.06

0.10

0.14

Jan-05 Apr-05 Jul-05 Oct-05 Jan-06

A/c

m

J.Das - 3/8/06

What does MWRA test for?

After Treatment• Disinfection Contact Time (CT)• Total Coliform• Chlorine Residual• DBPs• Contaminants (again)

Disinfection Contact Time Standard

Giardia CT AchievementCarroll Water Treatment Plant

0

200

400

600

800

1000

1-Jan-06 10-Jan-06 19-Jan-06 28-Jan-06

% C

T Ac

hiev

ed

Regulatory Minimum Standard

Disinfection By-ProductsTotal Trihalomethanes

TTHM Running Annual AveragesAt Compliance Locations For CVA, MetroWest, and

Metro Boston Sites

0

20

40

60

80

100

120

Jan-02 Jan-03 Jan-04 Jan-05 Jan-06

TTH

Ms

(ug/

L)

M etroWest & M etro Boston CVA

EPA Standard

DBPs - HAAsHAA Running Annual Averages

At Compliance Locations For CVA, MetroWest, andMetro Boston Sites

0

20

40

60

80

100

120

Jan-02 Jan-03 Jan-04 Jan-05 Jan-06

HAA

5 (u

g/L)

M etrWest & M etro Boston

CVA

EPA Standard

Developed vs. Developing Country Water Quality Standards and Compliance

• In the previous slides, we have learned about the US EPA Safe Drinking Water Act and looked closely at the example of water quality at the Massachusetts Water Resources Authority (MWRA) which provides drinking water to the cities and towns of Greater Boston.

• The graph to the right shows the contrast between developed and developing country circumstances when it comes to compliance with drinking water standards.

• Let’s now look at an example of challenges toward achieving water quality compliance in a developing country – Vietnam.

DEVELOPED COUNTRIES

Con

cent

ratio

n of

pol

luta

ntC

once

ntra

tion

of p

ollu

tant

Standard

periods ofnon-compliance observed

concentration

time

DEVELOPING COUNTRIES

Standard

whole period ofnon - compliance

observedconcentration

time

objective: to comply with the standard

Figure by MIT OpenCourseWare.

WHO Water Quality Guidelines

• Application of guidelines– Develop national laws, regulations, and

standards, based on guidelines and local conditions

– Implement a national compliance and surveillance program

– Surveillance and regulatory authorities should be separate from local water authorities due to conflicting priorities

• National standards may differ significantly from WHO guidelines

• “Stepwise” improvement

DEVELOPED COUNTRIES

Con

cent

ratio

n of

pol

luta

ntC

once

ntra

tion

of p

ollu

tant

Standard

periods ofnon-compliance observed

concentration

time

DEVELOPING COUNTRIES

Standard

whole period ofnon - compliance

observedconcentration

time

objective: to comply with the standard

Figure by MIT OpenCourseWare.

Vietnam – Some Stats

• Population = 83 million• GDP/capita ≈ $400/capita• % Access to Drinking Water = 77% • Urban with Access to Improved Sanitation = 84%• Estimated # affected by arsenic contamination of

drinking water supplies = 6 – 10 million

Vietnam - Water Quality Management

• Ministry of Natural Resources and Environment (MONRE) is responsible for federal management of natural resources (land, water, air). This is a newly established ministry that has taken authority from the Ministry of Rural Development to streamline overall management.

• Ministry of Health (MOH), Dept of Preventive Medicine, is responsible for National Water Quality Standards, which in Vietnam includes more than 50 water quality parameters –microbiological, chemical, physical.

Examples of National Environmental Strategy Programs (35 total) 2010 - 2020

Program Priority Date to Finish

Agencies

Hazardous Medical Waste Treatment

Highest Phase 12010

MoH

Targets for rural clean drinking water

Higher Phase 1 2010

MARD

Seriously polluted waterways

High Phase 12010

MoC, MoT

Env. Consequence of American chemical warfare

highest 2010 MoNRE

Vietnam - Water Quality Regulations

• Vietnam follows essentially the same water quality limits as recommended by the WHO Guidelines for Drinking Water Quality

• Vietnam’s water quality regulations describe 3 groups of drinking water contaminants: A, B, and C.

• Group A (15 parameters) requires monthly reporting.• Group B requires one-time reporting at the time of the

installation of the water supply. (Arsenic, for example, is in this group).

• Group C is done on request. • There is currently no national database of water quality. • All 64 provinces should be sending monthly reports for

Group A contaminants to MOH. In practice, about 25-30 out of 64 provinces send in monthly reports.

Vietnam Water Quality• Large urban areas (e.g. Hanoi, Haiphong, Ho Chi Minh City), supplied

by the state water systems, have treated water supplies with fairly good microbiological water quality, except during exceptional events, such as flooding.

• Distribution System Contamination: Water discharged from WTPs may be of good microbiological quality, but it becomes contaminated in the distribution system.

• Rural Water - almost 70% of provinces don’t meet the microbiological (total coliform/E.Coli) standard of 0 CFU/100 ml – There is the need for new standards for rural areas.

• Some Water-Related Health Problems: typhoid, diarrhea, dengue fever, arsenicosis.

• Unfortunately, there are very few actions to address these health problems because there is no budget to do so.

• Provincial Centers have very small budgets for water quality. • Disease outbreaks are comparatively easy to control; however,

Chemical Contamination is a big problem because provincial centers don’t have the capacity to address chemical contamination.

Financing of Ministry of Health, Dept. of Preventive Medicine

• DANIDA supports MoH Dept of Preventive Medicine from 2000-2005. In 2006 -2010, DANIDA will provide $100M to Vietnam overall. 30-50% of this $100M is expected to go to the MOH for sanitation projects.

• UNICEF provides the MOH with $200,000 - $300,000/year, and that money goes to support 15 District offices.

• The Gov’t of Vietnam provides MOH with a budget of $70,000/year ( = 1 B VND/year). The gov’t budget covers nominal salaries and running costs of the office. It also supports their hygiene behavior change/IEC (Information, Education and Communication) program.

• Dept. of Preventive Medicine Staff = 30 people. Government salary of Mr. Dang is typical – about $200/month. This is barely enough to support a family in Hanoi.

References• Gundry SW et al. 2006. Contamination of drinking water

between source and point-of-use in rural households of South Africa and Zimbabwe: implications for monitoring the Millennium Development Goal for water. Water Practice and Technology 1 (2)

• HACH. Undated. Current Technology for Chlorine Analysis. Booklet No. 17. Loveland, CO.

• Metcalf & Eddy. 2003. Wastewater Engineering.4th Ed. McGraw Hill. Boston.

• WHO, 2004.Guidelines for Drinking Water Quality. 3rd Edition. http://www.who.int/water_sanitation_health/dwq/gdwq3/en/index.html

• WHO, 1997. Guidelines for Drinking Water Quality, 2nd Edition. Vol. III, Surveillance and Control of Community Supplies, Geneva

• U.N. Millennium Task Force. 2005. http://unmillenniumproject.org/reports/tf_watersanitation.htm